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Search Publications by: Ian Bell (Fed)

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Displaying 1 - 25 of 88

temo: teqp-based model optimization

December 10, 2024
Author(s)
Ian Bell
The temo library is a set of building blocks that facilitate the automation of fitting models to experimental data for thermodynamic properties. The library is written in Python to enable broad re‐use and is based upon the suite of thermodynamic equations

Linking excess entropy and acentric factor in spherical fluids

September 9, 2024
Author(s)
Tae Jun Yoon, Ian Bell
Introduced by Kenneth Pitzer in 1955, the acentric factor (ω) became a standard quantity in chemical thermodynamics, representing a molecule's "shape" effect on the deviation from the corresponding state behavior. Nevertheless, its interpretation remains

High-Glide Refrigerant Blends in High-Temperature Heat Pumps: Part 2 - Inline Composition Determination for Binary Mixtures

May 10, 2024
Author(s)
Leon Brendel, Silvan Bernal, Carl Hemprich, Aaron Rowane, Ian Bell, Dennis Roskosch, Cordin Arpagus, Andre Bardow, Stefan Bertsch
Refrigerant mixtures are frequently used in air-conditioners and heat pumps. However, mixtures with high glides of 30 K and more during evaporation are rare, partially because there is an increased concern about composition shifts within the system. An

Superancillary Equations for the Multiparameter EOS in REFPROP 10.0

March 8, 2024
Author(s)
Ian Bell
Superancillary equations have been developed for the default multiparameter equations of state (EOS) for all 147 pure fluids in NIST REFPROP 10.0. These superancillary equations represent the orthobaric densities and saturation pressure of the EOS by

A branch-and-bound algorithm with growing datasets for large-scale parameter estimation

February 23, 2024
Author(s)
Susanne Sass, Alexander Mitsos, Dominik Bongartz, Ian Bell, Nikolay Nikolov, Angelos Tsoukalas
The solution of nonconvex parameter estimation problems with deterministic global optimization methods is desirable but challenging, especially if large measurement data sets are considered. We propose to exploit the structure of this class of optimization

EOS-CG-2021: A Mixture Model for the Calculation of Thermodynamic Properties of CCS Mixtures

November 16, 2023
Author(s)
Tobias Neumann, Stefan Herrig, Ian Bell, Robin Beckmuller, Eric W. Lemmon, Monika Thol, Roland Span
Thermodynamic properties for CCS-relevant mixtures can be calculated with the fundamental equation of state presented in this work over wide ranges of pressure, temperature, and composition for gas, liquid, and supercritical states, as well as phase

New Equation of State Constraints in the Critical Region

October 17, 2023
Author(s)
Ian Bell, Eric W. Lemmon
In this work, two classes of defects with multiparameter equations of state are investigated. In the first, it is shown that the critical point provided by equation of state developers often does not exactly meet the criticality conditions based on the

Non-flammable Low-GWP Refrigerant Blends to Replace HFC-134a

September 11, 2023
Author(s)
Harrison M. Skye, Piotr A. Domanski, Mark O. McLinden, Valeri I. Babushok, Ian Bell, Tara Fortin, Michael Hegetschweiler, Mark A. Kedzierski, Dennis Kim, Lingnan Lin, Gregory T. Linteris, Stephanie L. Outcalt, Vance (Wm.) Payne, Richard A. Perkins, Aaron Rowane
Non-flammable, lower global-warming-potential (GWP) refrigerants are needed to replace HFC-134a (GWP=1300) in military equipment. We previously used thermodynamic cycle simulations to screen 100 000+ refrigerant blends and identified 23 candidate

Lower-GWP Non-Flammable Refrigerant Blends to Replace HFC-134a

August 21, 2023
Author(s)
Harrison M. Skye, Piotr A. Domanski, Mark O. McLinden, Valeri I. Babushok, Ian Bell, Tara Fortin, Michael Hegetschweiler, Marcia L. Huber, Mark A. Kedzierski, Dennis Kim, Lingnan Lin, Gregory T. Linteris, Stephanie L. Outcalt, Vance (Wm.) Payne, Richard A. Perkins, Aaron Rowane
Non-flammable, lower global-warming-potential (GWP) refrigerants are needed to replace HFC-134a (GWP=1300) in military equipment. We previously used thermodynamic cycle simulations to screen 100 000+ refrigerant blends and identified 23 candidate

Quantum Entropic Effects in the Liquid Viscosities of Hydrogen, Deuterium, and Neon

July 26, 2023
Author(s)
Ian Bell, Jacob Leachman, Albert Rigosi, Heather Hill
The extreme conditions have limited the availability and accuracy of experimental thermophys- ical property measurements for cryogens, particularly transport properties. Traditional scaling techniques such as corresponding states theory have long been

Towards Global Parameter Estimation Exploiting Reduced Data Sets

April 5, 2023
Author(s)
Susanne Sass, Angelos Tsoukalas, Ian Bell, Dominik Bongartz, Jaromil Najman, Alexander Mitsos
We focus on deterministic global optimization (DGO) methods for solving nonconvex parameter estimation problems. In estimation problems, realistic and accurate solutions require a fitting against huge measurement data sets often. However, many of the

Low-GWP Non-Flammable Alternative Refrigerant Blends for HFC-134a: Final Report

January 27, 2023
Author(s)
Piotr A. Domanski, Mark O. McLinden, Valeri I. Babushok, Ian Bell, Tara Fortin, Michael Hegetschweiler, Marcia L. Huber, Mark A. Kedzierski, Dennis Kim, Lingnan Lin, Gregory T. Linteris, Stephanie L. Outcalt, Vance (Wm.) Payne, Richard A. Perkins, Aaron Rowane, Harrison M. Skye
This project addresses the objectives of the Statement of Need number WPSON-17-20 "No/Low Global Warming Potential Alternatives to Ozone Depleting Refrigerants." Its goal was to identify low global-warming-potential (GWP), non-flammable refrigerants to

Entropy Scaling of Viscosity for Molecular Models of Molten Salts

January 9, 2023
Author(s)
Jeffrey Young, Ian Bell, Allan H. Harvey
Entropy scaling relates dynamic and thermodynamic properties by reducing the viscosity to be a function of only the residual entropy. Molecular simulations are used to investigate the entropy scaling of the viscosity of three models of sodium chloride and

Linking viscosity to equation of state using residual entropy scaling theory

October 13, 2022
Author(s)
Xiaoxian Yang, Xiong Xiao, Monika Thol, Markus Richter, Ian Bell
In our previous work, a residual entropy scaling (RES) approach was developed to link viscosity to residual entropy (a thermodynamic property calculated with an equation of state, EoS) using a simple polynomial equation for refrigerants. This work extends